Fast pressure drop in central heating system.

skycatcher

My oil fired central heating pressure is constantly dropping to zero within about 15 mins of using a filling loop to raise it to 1 bar. There is no discernable sign of where all this water is going as there are no damp patches anywhere. Would/should normal house insurance pay for an investigation?

Thanks, Brian

Hasbeen

No normal house insurance would not pay for an investigation.

Does your insurance have boiler breakdown cover?

I am assuming this is a  oil fired combi

skycatcher

It's not a combi but just old fashioned oil boiler. Don't think I have boiler cover but you think they would pay to get someone in to search for leak and dug up the floor and repair.... obviously less some big excess!

Jeepers_Creepers

Is it a condensing boiler?

Anyhoo, have you noticed anything unusual with the system pressure over the past while - such as large fluctuations as the boiler fires up? How did you notice the pressure drop? Is the system pressure something you are aware of on, say, a weekly basis - if so, what's it been doing?

There will be a safety discharge pipe - usually 15mm copper - coming from the boiler or nearby and heading out through a house wall, ending up pointing at the ground. Can you find this? Cool - is there any water coming out of it especially when you top-up the system?

FreeBear

If you have concrete floor, and the pipes run under it, lift the carpet/vinyl. If there are any leaks, they may well be visible as damp patches in the concrete.

Hasbeen

skycatcher said:

It's not a combi but just old fashioned oil boiler. Don't think I have boiler cover but you think they would pay to get someone in to search for leak and dug up the floor and repair.... obviously less some big excess!

If it is not covered, why would they do that?

If it is an old oil boiler, then would suggest you get an OFTEC engineer in to take a look.

skycatcher

Jeepers_Creepers said:

Is it a condensing boiler?

Anyhoo, have you noticed anything unusual with the system pressure over the past while - such as large fluctuations as the boiler fires up? How did you notice the pressure drop? Is the system pressure something you are aware of on, say, a weekly basis - if so, what's it been doing?

There will be a safety discharge pipe - usually 15mm copper - coming from the boiler or nearby and heading out through a house wall, ending up pointing at the ground. Can you find this? Cool - is there any water coming out of it especially when you top-up the system?

It's older than condensing boilers! I moved into this house in the summer and wasn't until a month or so ago I became aware of fluctuating heat in the radiators. My in investigations lead to identifying the pressure drop. The pressure vessel membrane was busy so got that replaced and hours that would be the problem fixed but if anything the pressure drop has become faster.

skycatcher

FreeBear said:

If you have concrete floor, and the pipes run under it, lift the carpet/vinyl. If there are any leaks, they may well be visible as damp patches in the concrete.

That's a good idea....I was hoping to avoid lifting flooring but a couple of the downstairs have vinyl so hopefully it's not stuck down. The main room is laminate so how is not under there!

Jeepers_Creepers

The most obvious thing to check is the discharge pipe. ID that on the outside of your house, usually located close to where the boiler is fitted inside. Get a clear plastic bag and attach it on the end of that pipe using a rubber band. Refill the system and see if water comes out as the pressure drops.

You want the answer to be 'yes' :-)

stuart45

FreeBear said:

If you have concrete floor, and the pipes run under it, lift the carpet/vinyl. If there are any leaks, they may well be visible as damp patches in the concrete.

I had that problem in my cottage in the extension, not long after we moved in. Luckily my wife wanted a timber floor, so I put new pipes over the top of the concrete. 
Copper pipes in concrete floors often cause problems. 

skycatcher

Jeepers_Creepers said:

The most obvious thing to check is the discharge pipe. ID that on the outside of your house, usually located close to where the boiler is fitted inside. Get a clear plastic bag and attach it on the end of that pipe using a rubber band. Refill the system and see if water comes out as the pressure drops.

You want the answer to be 'yes' :-)

The boiler is located outside in a wee enclosure and appears not to have any discharge pipe. There is a pressure relief valve in the expansion vessel but it's dry (unfortunately)!